CN113315302A

CN113315302A - Linear motor

Info

Publication number: CN113315302A
Application number: CN202110595286.2A
Authority: CN
Inventors: 王俊恒; 李平; 南奋勇; 郭阳利
Original assignee: Shenzhen Zhaowei Machinery and Electronics Co Ltd
Current assignee: Shenzhen Zhaowei Machinery and Electronics Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2021-08-27

Abstract

The invention relates to the technical field of transmission, and provides a linear motor, which comprises: the outer surface of the fixed screw rod is provided with a first external thread; the transmission component comprises a transmission part with a hollow structure and a transmission nut, the transmission component is sleeved on the fixed screw rod, and the transmission nut is matched with the first external thread and can move along the axis direction of the fixed screw rod; and the driving mechanism is arranged in the fixed screw rod, and the power output end of the driving mechanism is connected with the transmission piece and used for driving the transmission assembly to rotate relative to the fixed screw rod. The driving device is arranged in the fixed screw rod with a hollow structure, so that the space is saved, and the miniaturization design is facilitated.

Description

Linear motor

Technical Field

The invention relates to the technical field of transmission, in particular to a linear motor.

Background

The linear motor usually adopts a screw rod and nut matching mode to realize the lifting or stretching of components such as a sleeve and the like, and is usually applied to devices needing lifting or stretching, such as a lifting upright post, an electric push rod and the like.

The existing devices such as the lifting upright column and the electric push rod are usually set to be multi-level lifting or multi-level telescopic, and the driving mechanism is arranged at the end part of the lifting assembly, so that the axial length or height of the lifting assembly is too large, and the requirement of a user on the lowest height cannot be met.

Disclosure of Invention

The invention aims to provide a linear motor to solve the technical problem of limited application scenes caused by the fact that the linear motor is large in whole in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that: there is provided a linear motor including:

the fixing screw rod is hollow inside and provided with a first external thread on the outer surface;

the transmission component comprises a transmission part in a hollow structure and a transmission nut arranged at one end of the transmission part, the transmission part and the transmission nut are both sleeved on the fixed screw rod, and the internal thread of the transmission nut is matched with the first external thread;

the driving mechanism is arranged in the fixed screw rod, and the power output end of the driving mechanism is connected with the transmission piece and used for driving the transmission piece to rotate relative to the fixed screw rod.

In one embodiment, the transmission member is a transmission screw rod, and the outer surface of the transmission screw rod is provided with a second external thread adapted to an external transmission structure.

In one embodiment, the inner surface of the transmission member is provided with a first limiting portion along the axial direction of the transmission member, and the driving mechanism includes:

the power part is fixed in the fixed screw rod and is provided with a power output shaft extending out of the fixed screw rod; and

the linkage piece is fixed on the power output shaft and is positioned inside the transmission piece, the linkage piece is provided with a first limiting matching part, and the first limiting matching part is in sliding fit with the first limiting part.

In one embodiment, the power part is a motor having the power output shaft connected to the linkage; or, the power part comprises a motor and a gear box connected to an output shaft of the motor, the gear box is provided with a power output shaft of the power, and the power output shaft is connected to the linkage.

In one embodiment, the drive nut has a mounting section and a base section connected to the mounting section, the mounting section extending into the drive member.

In one embodiment, the outer surface of the mounting section is provided with a limit groove structure matched with the first limit part; and/or the base section is connected to the transmission part through a screw.

In one embodiment, the second external thread has a direction of rotation opposite to the direction of rotation of the first external thread.

In one embodiment, the linear motor further comprises a lead screw nut threadedly engaged with the second external thread of the transmission.

In one embodiment, the linear motor further comprises a plurality of screw rod layer assemblies, each screw rod layer assembly is sequentially sleeved and assembled from inside to outside, and the screw rod layer assembly at the innermost layer is sleeved and assembled on the transmission part; the linear motor also comprises a screw rod nut which is sleeved on the outmost layer of the screw rod layer assembly.

In one embodiment, the linear motor further comprises a fixing part, and one end of the fixing screw rod is fixed to the fixing part; the fixing part is provided with a convex part, and the fixing screw rod is sleeved on the convex part; the shape of the outer surface of the protruding part is matched with the shape of the inner surface of the fixed screw rod so as to limit the relative rotation of the fixed screw rod and the protruding part.

One or more technical solutions described above in the embodiments of the present invention have at least the following technical effects or advantages:

the linear motor provided by the embodiment of the invention is provided with the fixed screw rod, the transmission assembly sleeved on the fixed screw rod and the driving mechanism of which the power output end is connected with the transmission assembly. Wherein, transmission assembly is including being hollow structure's driving medium and locating the drive nut of driving medium one end, and drive nut's internal surface has the internal thread, and the surface of stationary screw is equipped with first external screw thread, and drive nut's internal thread and first external screw thread looks adaptation promptly. The peripheral transmission mechanism is arranged on the outer surface of the transmission piece. Under the matching of the internal thread of the transmission nut and the first external thread, the transmission assembly can do linear motion along the axial direction of the fixed screw rod while doing rotary motion, so that the lifting or the stretching of the transmission assembly is realized. And the interior of the fixed screw rod is hollow, the driving mechanism is arranged in the fixed screw rod, and the power output end of the driving mechanism extends to the exterior of the fixed screw rod and is connected with the transmission assembly. So set up, actuating mechanism then does not occupy the exterior space, can improve space utilization, and more do benefit to the drive transmission subassembly and rotatory for fixed screw, shorten the connection cooperation length between actuating mechanism and the transmission subassembly, improve transmission stability.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is an exploded view of a linear motor according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a linear motor according to an embodiment of the present invention;

fig. 3 is a schematic top view of a linear motor according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3;

fig. 5 is a schematic structural diagram of the linear motor provided in the embodiment of the present invention, after the transmission assembly and the lead screw nut are removed;

fig. 6 is an exploded view of a transmission assembly of a linear motor according to an embodiment of the present invention.

Wherein, in the figures, the respective reference numerals:

100. a linear motor; 10. fixing the screw rod; 101. a first external thread; 20. a transmission assembly; 20a, a transmission member; 20b, a drive nut; 20b1, mounting section; 20b2, base segment; 20c, a limiting groove structure; 201. a second external thread; 30. a feed screw nut; 40. a drive mechanism; 41. a power section; 42. a linkage member; 50. a fixed part; 51. a protruding part; 202. a first limiting part; 410. a power take-off shaft; 420. a first limit matching part; 411. a motor; 412. a gear box.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1 to 4, the embodiment of the present invention provides a linear motor 100 for lifting or extending transmission, which can be applied to devices that need to perform lifting or extending functions, such as a lifting column, an electric push rod, a lifter, a lifting table, etc., but is not limited thereto; the linear motor 100 includes a fixing screw 10, a transmission assembly 20 and a driving mechanism 40, wherein:

the stationary screw 10 is fixedly arranged, i.e. does not perform a rotational movement nor a linear movement, the stationary screw 10 is hollow inside and the outer surface thereof is provided with a first external thread 101.

The transmission assembly 20 includes a transmission member 20a having a hollow structure and a transmission nut 20b disposed at one end of the transmission member 20a, the transmission member 20a and the transmission nut 20b are both sleeved on the fixed screw 10, and the transmission nut 20b is engaged with the first external thread 101 or screwed together, so that the transmission member 20a and the transmission nut 20b can make linear motion relative to the fixed screw 10 through the engagement of the internal and external threads when making rotational motion relative to the fixed screw 10.

The driving mechanism 40 is arranged in the hollow fixed screw rod 10, and the power output end of the driving mechanism is connected with the transmission piece 20a of the transmission assembly 20 and is used for driving the transmission assembly 20 to rotate relative to the fixed screw rod 10; the driving mechanism 40 is a mechanism or a device capable of providing a driving force and driving the transmission assembly 20 to rotate relative to the fixed screw 10, for example, the driving mechanism 40 may include a motor and a transmission member connected to an output end of the motor, and the transmission member drives the transmission assembly 20 to rotate relative to the fixed screw 10 by the driving force provided by the motor. Alternatively, the driving mechanism 40 may be a motor, and the output end of the motor directly drives the transmission assembly 20.

The linear motor 100 provided in the embodiment of the present application is provided with a fixing screw 10, a transmission assembly 20 sleeved on the fixing screw 10, and a driving mechanism 40 having a power output end connected with the transmission assembly 20. The transmission assembly 20 includes a transmission member 20a having a hollow structure and a transmission nut 20b disposed at one end of the transmission member 20a, an inner thread is disposed on an inner surface of the transmission nut 20b, and a first outer thread 101 is disposed on an outer surface of the fixed screw 10, i.e., the inner thread of the transmission nut 20b is matched with the first outer thread. The driving mechanism 40 drives the transmission assembly 20 to make a rotational motion relative to the fixed screw 10, and under the matching of the internal thread of the transmission nut 20b and the first external thread 101, the transmission assembly 20 can make a linear motion along the axial direction of the fixed screw 10 (i.e. the axial direction of the fixed screw 10) while making a rotational motion, so as to realize the lifting or the extension of the transmission assembly 20. And the fixing screw rod 10 is hollow, the driving mechanism 40 is arranged inside the fixing screw rod 10, and the power output end of the driving mechanism 40 extends to the outside of the fixing screw rod 10 and is connected with the transmission assembly 20. So set up, actuating mechanism 40 sets up in the inside of fixed screw 10, does not occupy the exterior space, can improve space utilization, and more do benefit to drive transmission assembly 20 and rotatory for fixed screw 10, shorten the connection cooperation length between actuating mechanism 40 and the transmission assembly 20, improve transmission stability.

Referring to fig. 1 and 2, the transmission member 20a is a transmission screw rod, and a second external thread 201 adapted to an external transmission structure is disposed on an outer surface of the transmission screw rod. The driving mechanism 40 drives the transmission assembly 20 to make a rotational motion relative to the fixed screw rod 10, under the matching of the internal thread of the transmission nut 20b and the first external thread 101, the transmission assembly 20 can make a rotational motion and simultaneously make a linear motion along the axial direction of the fixed screw rod 10 (i.e. the axial direction of the fixed screw rod 10), so as to realize the lifting or the extension and the retraction of the transmission assembly 20, at the same time, the rotation of the transmission screw rod can drive the peripheral transmission mechanism in threaded matching with the second external thread 201 to make a linear motion along the axial direction of the transmission screw rod through the second external thread 201, so that the peripheral transmission mechanism in threaded matching with the second external thread 201 moves axially relative to the fixed screw rod 10 along with the transmission screw rod, namely, when the transmission screw rod 2 moves relative to the fixed screw rod 10, the peripheral transmission mechanism in threaded matching with the second external thread moves relative to the transmission screw rod, the rapid lifting or stretching of the peripheral transmission mechanism in threaded fit with the second external thread 201 is realized, and then the rapid lifting or stretching of the lifting upright post, the electric push rod and other devices adopting the linear motor 100 is realized, so that the lifting or stretching efficiency is effectively improved.

In another embodiment, the transmission member 20a is a hollow tube, and the external transmission structure is fixedly connected to the hollow tube. It can be understood that, in this case, the peripheral transmission structure or the mechanism to be transmitted is directly fixed on the outside of the hollow tube, i.e. it is driven by the hollow tube to move telescopically along the axial direction of the fixed screw rod 10, and at this time, the primary transmission of the peripheral transmission structure is realized.

In one embodiment, referring to fig. 1 and 2, the linear motor 100 further includes a fixing portion 50, and one end of the fixing screw 10 is fixed to the fixing portion 50; the fixing portion 50 may be a base, the fixing screw 10 may be vertically fixed to the fixing portion 50, the fixing portion 50 may also be a base, the fixing screw 10 may be transversely fixed to the fixing portion 50, and of course, the fixing portion 50 may also be other structures. So set up, the fixed part 50 can fix the lead screw 10, prevents that the lead screw 10 from removing, reinforcing stability.

It should be noted that, in some other embodiments, the fixing portion 50 may not be disposed on the linear motor 100, and the fixing screw 10 may be directly fixed to a device to which the linear motor 100 is applied, for example, the fixing screw 10 may be directly fixed to a housing of the lifting column.

Optionally, in an embodiment, referring to fig. 2 and fig. 4, the fixing portion 50 has a protruding portion 51, the fixing screw 10 is sleeved on the protruding portion 51, that is, the protruding portion 51 is inserted into the protruding portion 51, and the protruding portion 51 is matched with the cavity of the fixing screw 10, so that the fixing screw 10 is prevented from swinging or moving relative to the fixing portion 50, and the stability of the fixing screw 10 is improved.

In other embodiments, the protruding portion 51 may not be provided, for example, the fixing screw 10 and the fixing portion 50 are directly fixedly connected by a screw, a bolt, a rivet, a welding, or the like.

Alternatively, in one embodiment, referring to fig. 2 and 4, the outer surface shape of the protruding portion 51 matches the inner surface shape of the cavity of the fixing screw 10 to limit the relative rotation between the fixing screw 10 and the protruding portion 51; the protruding portion 51 is a non-cylindrical protruding portion, which can limit the relative rotation between the stationary screw 10 and the protruding portion 51, for example, the protruding portion 51 may be a prism (e.g., a quadrangular prism), a convex column with an elliptical cross section, or other regular or irregular convex columns. So set up, protruding portion 51 and the cooperation of the cavity of stationary screw 10 of establishing can prevent that stationary screw 10 from taking place to rotate, further provides its steadiness, and then improves transmission assembly 20 and makes rotary motion and linear motion's stability for stationary screw 10.

Alternatively, in one embodiment, referring to fig. 4, the fixing screw 10 is detachably fixed on the fixing portion 50, for example, the fixing screw 10 may be fixed on the fixing portion 50 by a screw or a bolt. So configured, the detachment and installation between the fixing screw 10 and the fixing portion 50 is facilitated.

In one embodiment, referring to fig. 2 and 4, the rotation direction of the second external thread 201 is opposite to that of the first external thread 101, so that the moving direction of the peripheral transmission mechanism screwed to the second external thread 201 during linear motion is the same as that of the transmission screw rod during linear motion, thereby realizing that the peripheral transmission mechanism screwed to the second external thread 201 and the transmission member 20 simultaneously lift or extend in the same direction; the direction of rotation is the direction of the screw thread, and the screw thread that is rotated clockwise is called a right-hand screw thread, and the screw thread that is rotated counterclockwise is called a left-hand screw thread.

In one embodiment, referring to the drawings, the inner surface of the transmission member 20a is provided with a plurality of first position-limiting portions 202 along the axial direction of the transmission member 20a, the driving mechanism 40 includes a power portion 41 and a linking member 42, the power portion 41 is fixed to the stationary screw 10, specifically, the power portion 41 can be fixed to the inside of the stationary screw 10, for example, the power portion 41 can be fixed to the inside of the stationary screw 10 by clamping, welding, screwing or bolting, but not limited thereto, the power portion 41 is located at an end of the stationary screw 10 away from the fixing portion 50, the power portion 41 has a power output shaft 410, the power output shaft 410 extends to the outside of the stationary screw 10, the linking member 42 is fixed to the power output shaft 410 and located inside the transmission assembly 20, the linking member 42 has a plurality of first position-limiting engaging portions 420, the first position-limiting engaging portions 420 are slidably engaged with the first position-limiting portions 202, the linkage member 42 and the transmission assembly 20 can be limited to rotate relatively and can only do relative linear motion; the linkage 42 is an intermediate power transmission member capable of transmitting the rotation power of the power output shaft 410 to the transmission assembly 20, for example, the linkage 42 may be a spline, a cylindrical linkage, a fan-shaped linkage, a strip-shaped linkage, or other regular or irregular linkage; specifically, the first limiting portion 202 may be a protruding strip protruding from the inner surface of the transmission assembly 20 along the axial direction of the transmission assembly 20, the first limiting engaging portion 420 may be a sliding slot protruding from the outer peripheral surface of the linkage member 42, or the first limiting portion 202 may be a sliding slot recessed from the inner surface of the transmission assembly 20 along the axial direction of the transmission assembly 20, and the first limiting engaging portion 420 is a protruding strip or protrusion protruding from the outer peripheral surface of the linkage member 42, and the sliding slot and the protruding strip or protrusion are slidably engaged with each other, so as to limit the relative rotation between the linkage member 42 and the transmission assembly 20, so that the transmission assembly 20 can be driven to rotate when the linkage member 42 rotates, and the transmission assembly 20 can perform a relative linear motion with the linkage member 42 when performing a linear motion with respect to the fixed lead screw 10. During operation, the power portion 41 acts, the power output shaft 410 drives the linkage member 42 to rotate, the linkage member 42 drives the transmission assembly 20 to rotate through the cooperation of the first limiting portion 202 and the first limiting matching portion 420, the transmission assembly 20 moves linearly relative to the fixed screw 10 under the cooperation of the first internal thread 201 and the first external thread 101, the transmission assembly 20 and the linkage member 42 move linearly relative to each other, and the linkage member 42 can play a role in supporting and stabilizing the transmission assembly 20. So set up, do benefit to actuating mechanism 40 and stably drive transmission assembly 20 and do rotary motion and linear motion simultaneously for stationary screw 10 for cooperation compact structure, stability is high between stationary screw 10, actuating mechanism 40 and the transmission assembly 20.

Alternatively, in an embodiment, referring to fig. 2 and fig. 4, the power part 41 includes a motor 411 and a gear box 412, the motor 411 is installed inside the fixed screw 10, an input end of the gear box 412 is connected with an output shaft of the motor 411, the gear box 412 has a power output shaft 410, and specifically, both the motor 411 and the gear box 412 are fixed inside the fixed screw 10; it will be appreciated that the gearbox 412 may be any of the existing gearboxes; in operation, the power unit 41 operates, and the power of the motor 411 is transmitted from the output shaft thereof to the gear box 412, transmitted from the gear train inside the gear box 412 to the power output shaft 410, and transmitted to the link 42.

It should be noted that the structure of the power portion 41 is not limited to this, and in some other embodiments, the power portion 41 may be a speed reducing motor, and the speed reducing motor has a power output shaft 410. In one embodiment, the drive mechanism 40 is an electric motor having a power output shaft coupled to a linkage.

In one embodiment, referring to fig. 1, 4 and 6, the driving nut 20b has a mounting section 20b1 and a base section 20b2 connected to the mounting section 20b1, the mounting section 20b1 extending into the driving member 20 a. It will be appreciated that the drive nut is provided with a quick connection to the drive member 20a, and with a stable connection. When the mounting section 20b1 is installed, it can extend into the driving member 20a to perform positioning and supporting functions.

In one embodiment, referring to fig. 6, the mounting section 20b1 has a limiting groove structure 20c formed on an outer surface thereof for matching with the first limiting portion 202. It can be understood that the connection stability of the transmission member 20a and the transmission nut 20b is further improved by the matching of the first position-limiting portion 202 and the position-limiting groove structure 20 c. That is, when the driving member 20a and the driving nut 20b are connected by a screw, the screw is subjected to a shearing force by a torsional force therebetween, and is easily broken. And, first spacing portion can be for the protruding muscle that sets up along the axial of driving medium 20a to and, spacing groove structure 20c also sets up along the axial of erection segment 20b1, and like this, the nut section forms the cohesion with the lead screw section in the circumferential direction, and connection stability promotes greatly. At the same time, in order to further provide stability between the drive nut and the drive member 20a, screws are screwed into the end face of the drive member 20a at the end face of the base section 20b 2.

Optionally, in one embodiment, the screw rod layer assembly includes a plurality of hollow screw rods, the hollow screw rods are hollow inside, internal threads are arranged on the inner surfaces of the hollow screw rods, external threads are arranged on the outer surfaces of the hollow screw rods, each hollow screw rod is sleeved from inside to outside in sequence, and the internal threads of the hollow screw rod on the outer layer of the two adjacent hollow screw rods are matched or screwed with the external threads of the hollow screw rod on the inner layer; the hollow screw rod at the innermost layer is sleeved on the transmission piece 20a, and the internal thread of the hollow screw rod at the innermost layer is matched or screwed with the second external thread 201 of the transmission piece 20 a. The second external thread 201 drives each hollow screw rod to do linear movement and/or rotary movement through the rotation of the transmission piece 20a, so that multi-stage lifting or stretching is realized. For those skilled in the art, parameters such as the lead angle of the second external thread 201 and the external threads of each hollow screw rod can be set according to the actual application requirement.

Optionally, in an embodiment, the lead screw layer assembly includes a driven lead screw and a nut body, the driven lead screw is hollow inside, an external thread is provided on an outer surface of the driven lead screw, and the nut body is fixedly connected with one end of the driven lead screw, i.e. the structure form of the lead screw layer assembly is the same as that of the transmission assembly 20. The driven screw rod of the innermost screw rod layer assembly is sleeved on the transmission piece 20a, the nut main body of the innermost screw rod layer assembly is in threaded fit with the second external thread 201, and the driven screw rod of the innermost screw rod layer assembly is in threaded fit with the transmission piece 20 a; when the number of the screw rod layer assemblies is one, the screw rod layer assembly on the outermost layer and the screw rod layer assembly on the innermost layer are the same; the transmission part 20a can drive each screw rod layer assembly to rotate and move along the axial direction of the transmission part 20a, so that four-stage and more than four-stage multi-stage lifting or stretching is realized.

Specifically, when the number of the screw rod layer assemblies is one, the driving mechanism 40 drives the driving member 20a to perform rotary motion and linear motion, the driving member 20a drives the driven screw rod to rotate when performing rotary motion, and simultaneously the nut of the screw rod layer assembly is driven to perform linear motion relative to the driving member 20a through the second external thread 201, so that the driven screw rod performs linear motion and rotary motion simultaneously, and the driven screw rod performs rotary motion.

Specifically, when the number of the screw rod layer assemblies is two or more, the transmission member 20a is sleeved with the innermost screw rod layer assembly, the driven screw rod of the innermost screw rod layer assembly is sleeved with the driven screw rod of the sub-inner screw rod layer assembly, the nut of the sub-inner screw rod layer assembly is in threaded fit with the external thread of the driven screw rod of the innermost screw rod layer assembly, the driven member of the sub-inner screw rod layer assembly is fixed on the driven screw rod of the innermost screw rod layer assembly, and so on, the screw rod layer assemblies are sequentially sleeved from inside to outside for assembly, the screw rod layer assemblies can be driven to rotate and move along the axial direction of the transmission member 20a through the rotation motion and the linear motion of the transmission member 20a, and the multistage lifting or stretching of five stages and more than five stages can be realized.

In one embodiment, referring to fig. 1 and 4, the linear motor 100 further includes a lead screw nut 30, the lead screw nut 30 is sleeved on the transmission member 20a, an inner thread is provided on an inner surface of the lead screw nut 30, the lead screw nut 30 can be limited by a device to which the linear motor 100 is applied to limit the rotation of the lead screw nut 30, and the transmission member 20a can drive the lead screw nut 30 to move along an axial direction of the transmission member 20a through a second outer thread 201; the lead screw nut 30 is sleeved on the transmission member 20a, which means that the lead screw nut 30 is directly sleeved on the transmission member 20a or sleeved on the transmission member 20a through an intermediate component; in one way, the screw nut 30 can be directly sleeved on the transmission member 20a and screwed to the second external thread 201, and when the transmission member 20a rotates, the screw nut 30 is directly driven to make linear motion through the second external thread 201, in this case, the fixed screw 10 can be regarded as a first stage, the transmission member 20a can be regarded as a second stage, and the screw nut 30 can be regarded as a third stage, thereby realizing three-stage lifting or stretching.

In another embodiment, the lead screw nut 30 is sleeved on the lead screw layer assembly, and the driving member 20a drives the lead screw layer assembly to move linearly through the second external thread 201 when rotating, so as to indirectly drive the lead screw nut 30 to move linearly. For example, the screw layer assembly may be a hollow screw sleeved on the transmission member 20a, and the screw nut 30 may be in threaded fit with the outermost hollow screw, in this case, when the hollow screw is one, the fixed screw 10 may be regarded as a first stage, the transmission member 20a may be regarded as a second stage, the hollow screw may be regarded as a third stage, and the screw nut 30 may be regarded as a fourth stage, thereby achieving four-stage lifting or telescoping, and so on, the hollow screws may be provided in plurality, each hollow screw may be sequentially sleeved from inside to outside, and the screw nut 30 is in threaded fit with the outermost hollow screw, thereby achieving multi-stage lifting or telescoping.

Alternatively, in an embodiment, referring to fig. 1 and fig. 4, the lead screw nut 30 is screwed to the second external thread 201 of the transmission member 20a, that is, the internal thread of the lead screw nut 30 is fitted or screwed to the second external thread 201, the transmission member 20a is driven to rotate and linearly move relative to the fixed lead screw 10 by the linkage member 42 of the driving mechanism 40, the transmission member 20a drives the lead screw nut 30 to linearly move relative to the transmission member 20a, at this time, the fixed lead screw 10 can be regarded as a first stage, the transmission member 20a can be regarded as a second stage, and the lead screw nut 30 can be regarded as a third stage, so that three-stage lifting or extension is realized, the stability is high, and the transmission member 20a and the lead screw nut 30 are lifted or extended simultaneously, and the efficiency can be improved.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A linear motor, characterized in that the linear motor comprises:

2. A linear motor according to claim 1, wherein: the transmission part is a transmission screw rod, and second external threads matched with the external transmission structure are arranged on the outer surface of the transmission screw rod.

3. A linear motor according to claim 1, wherein: the internal surface of driving medium is followed the axial of driving medium is equipped with first spacing portion, actuating mechanism includes:

4. A linear motor according to claim 3, wherein: the power part is a motor, the motor is provided with the power output shaft, and the power output shaft is connected to the linkage piece; or, the power part comprises a motor and a gear box connected to an output shaft of the motor, the gear box is provided with a power output shaft of the power, and the power output shaft is connected to the linkage.

5. A linear motor according to claim 3, wherein: the transmission nut is provided with an installation section and a base section connected to the installation section, and the installation section extends into the transmission part.

6. A linear motor according to claim 5, wherein: a limiting groove structure matched with the first limiting part is formed in the outer surface of the mounting section; and/or the base section is connected to the transmission part through a screw.

7. A linear motor according to claim 2, wherein: the second external thread has a direction of rotation opposite to the direction of rotation of the first external thread.

8. A linear motor according to claim 2, wherein: the linear motor further comprises a screw rod nut, and the screw rod nut is in threaded fit with the second external thread of the transmission piece.

9. A linear motor according to any one of claims 1 to 5, characterized in that: the linear motor also comprises a plurality of screw rod layer assemblies, each screw rod layer assembly is sequentially sleeved and assembled from inside to outside, and the screw rod layer assembly at the innermost layer is sleeved on the transmission part; the linear motor also comprises a screw rod nut which is sleeved on the outmost layer of the screw rod layer assembly.

10. A linear motor according to claim 1, wherein: the linear motor also comprises a fixing part, and one end of the fixing screw rod is fixed on the fixing part; the fixing part is provided with a convex part, and the fixing screw rod is sleeved on the convex part; the shape of the outer surface of the protruding part is matched with the shape of the inner surface of the fixed screw rod so as to limit the relative rotation of the fixed screw rod and the protruding part.